The present invention relates to a vacuum cleaner nozzle comprising a nozzle body having a nozzle or suction opening facing a surface to be cleaned, and one or more scraper blades extending downwardly from the nozzle body adjacent the nozzle opening. Such scraper blades have a single, strip-shaped piece, made from rubber, plastic or some other elastic material. The strip-shaped pieces have a first edge part resting on the surface to be cleaned and a second or opposite edge part which is secured to or mounted in a holder in the nozzle body. The distance of the nozzle body from the surface to be cleaned is mainly constant when the scraper blade is moved forwards or rearwards on a hard surface. The length of the strip-shaped piece extending towards the surface from the holder under free conditions is larger than the distance between the surface and the nozzle body so that the first edge part during forward and rearward movement will trail behind the holder as seen in the direction of movement of the nozzle.
Nozzles of the type described above are previously known. These nozzles are used on soft as well as hard surfaces and comprise a bottom plate facing the surface to be cleaned and have an elongated nozzle or suction opening extending generally perpendicular or transverse to the direction of movement of the nozzle. The nozzle is supported on a hard surface by means of several wheels which, with regard to flow conditions, define an optimal distance between the nozzle opening and the hard surface being cleaned.
Relatively behind the nozzle opening and parallel with it there are one or more rubber blades. These blades have a free length extending from the bottom plate toward the floor, the length being somewhat larger than the distance between the surface and the bottom plate. Such blades are used to convey dirt on a hard surface when moving the nozzle forwards, but they do not hinder the movement of the nozzle on a soft surface. Since the extending free length of the rubber blade is larger than the distance between the surface being cleaned and the bottom plate, the rubber blade will be somewhat curved when in contact with the surface, and the lower edge of the blade will trail with respect to the support point of the scraper blade in the nozzle. If the scraper blade is to perform properly, it has to be comparatively stiff so that the dirt really is conveyed by the scraper blade to the nozzle inlet when the nozzle is moved on a hard surface.
However, the use of a scraper blade also creates a disadvantage since the scraper blade, when the nozzle is moved on a surface, will lift the nozzle vertically when the nozzle is moved back and forth across the surface being cleaned. This is because the scraper blade, when the nozzle is moved in one direction (i.e., either forwardly or rearwardly), is first curved in one direction but, when the direction of nozzle movement is reversed, the nozzle first pivots about the blade, causing the blade to straighten and lift the nozzle off vertically from the floor. Thereafter, the scraper blade will curve in a second direction, opposite to the first, as the nozzle is moved in the opposite direction (i.e., either rearwardly or forwardly). Therefore, there exists a need in the art for a scraper blade which does not lift the nozzle during a change in direction of nozzle movement.